Re: [Qemu-devel] [PATCH v1] s390x/kvm: Configure page size after memory has actually been initialized

[David Hildenbrand]

On 27.03.19 17:45, Igor Mammedov wrote:
> On Wed, 27 Mar 2019 14:59:44 +0100
> David Hildenbrand <address@hidden> wrote:
> 
>> Right now we configure the pagesize quite early, when initializing KVM.
>> This is long before system memory is actually allocated via
>> memory_region_allocate_system_memory(), and therefore memory backends
>> marked as mapped.
>>
>> Instead, let's configure the maximum page size after initializing
>> memory in s390_memory_init(). cap_hpage_1m is still properly
>> configured before creating any CPUs, and therefore before configuring
>> the CPU model and eventually enabling CMMA.
>>
>> We might later want to replace qemu_getrampagesize() by another
>> detection mechanism, e.g. only looking at mapped, initial memory.
>> We don't support any memory devices yet, and if so, we can always reject
>> devices with a page size bigger than the initial page size when
>> hotplugging. qemu_getrampagesize() should work for now, especially when
>> converting it to only look at mapped backends.
>>
>> Signed-off-by: David Hildenbrand <address@hidden>
> 
> Acked-by: Igor Mammedov <address@hidden>

BTW, do we want

qemu_getmaxrampagesize()
qemu_getminrampagesize()

or similar. qemu_getrampagesize() in its current form is really far from
beautiful.

-- 

Thanks,

David / dhildenb